Rationale: Social anxiety disorder in adolescents is associated with multiple impairments, and is stable into adulthood. Despite promising clinical treatments, most socially anxious adolescents are unidentified and untreated. By delivering interventions in school, treatment accessibility is optimized. We have developed a 12- week cognitive-behavioral, school-based group intervention, Skills for Social and Academic Success (SASS). Two controlled trials support the efficacy of SASS implemented by clinical psychologists, compared to 1) a no- treatment condition, and 2) an attention control. SASS superiority was maintained six months post-treatment (Masia Warner et al., 2005; Masia Warner et al., 2007). To promote SASS's sustainability in schools, we propose to evaluate SASS implemented by school personnel. Objective: This 5-year study addresses the unmet needs of adolescents with social phobia through the testing of SASS delivered by trained school counselors (SC-SASS), compared to a nonspecific school counseling program, Skills for Living (SFL). A secondary goal is to provide further examination of the efficacy of SASS delivered by psychologists (Expert- SASS), compared to SFL. Hypotheses: Both SC-SASS and Expert-SASS will be superior to SFL in reducing the severity and rate of social anxiety disorder and in improving overall and school functioning, immediately following treatment and six months after. Methods: Subjects. One hundred twenty-six 9th through 11th graders (ages 14-17), in two public high schools, will be screened with standard social anxiety scales. Parents of those scoring in the top 15% will be called. Adolescents who are reported to be socially anxious will be systematically evaluated by independent evaluators. Those who meet criteria for social anxiety disorder will be enrolled. Treatments. Participants will be randomized to one of three treatments: 1) SASS delivered by school counselors (SC-SASS), 2) SASS delivered by psychologists (Expert-SASS), or 3) a nonspecific school counseling program (SFL). Assessments with parents and adolescents, at baseline, post-intervention, and 6 months later, will include diagnosis, illness severity, scale ratings of social anxiety and depression, clinical global improvement, and overall and school function. Data analyses. Outcomes will be analyzed using linear and generalized linear mixed models. Significance: The study has high public health significance given 1) the under-recognition and treatment of social anxiety in adolescents; 2) schools' role as primary mental health services providers, and 3) increased demand for schools to address students' emotional needs. It will provide information on the value of training frontline professionals in evidence-based therapy, and can serve as a model for promoting efficacious care to underserved youth. Public Health Relevance: The study investigates whether school-based CBT for social anxiety disorder, delivered by school counselors, is effective. This effort is particularly significant given the underutilization of mental health services by youth with psychiatric disorders, and the increased demand for school services to enhance treatment accessibility. This application has considerable public health relevance since it will provide information on the value of training frontline professionals in evidence-based treatments, and potentially serve as a model for promoting efficacious care for underserved youth with social anxiety disorder, as well as other psychiatric disorders.